1. Field of the Invention
The present invention relates generally to cantilever support structures for signs and other articles, and more specifically to a flexible support for such signs and articles. The support is formed generally of a plurality of relatively thin sheets of material laminated together, with the flexibility of each of the sheets providing sufficient flexibility to xe2x80x9cgivexe2x80x9d when struck by a car or the like. Each of the thin components is curved about its elongate axis, in order to provide sufficient stiffness for the support of a sign or the like under normal conditions.
2. Description of the Related Art
Traffic information, warning, directional, and other signs have been known since shortly after the development of the motor vehicle. Such signs are a critical part of our road transportation system, and oftentimes the removal of a single sign from a critical location, can be disastrous. This can occur when a stop sign is removed from a busy intersection, or perhaps where a vehicle inadvertently knocks down a row of lane delineators marking a lane shift, curve, or other potential hazard.
It will be seen that the need for durable sign posts or supports for such signs is critical in many cases. Nevertheless, such markers and signs are installed and maintained by various governmental agencies, which operate under certain budgetary constraints. While it is possible to construct such sign supports which are sufficiently durable to withstand years of service in the outdoor environment, it is difficult to do so at a reasonable cost, and particularly to fabricate such supports in a manner that is not hazardous to traffic. Flexible plastic delineator posts have been developed in the past, but such posts are easily run down and damaged by some drivers, and the plastic material is subject to weakening and degradation by exposure to sunlight (ultraviolet).
Alternatively, xe2x80x9cbreakawayxe2x80x9d sign posts and supports have been developed for installation in many areas, but are relatively costly due to their specifically configured weak points in order to allow them to be snapped off or broken upon impact. While such breakaway posts and supports may increase safety for the vehicle impacting the support post or column, surrounding traffic and property may be endangered by the sign and column as it becomes a projectile after breaking away upon impact. In addition, the problem exists of the lack of a sign at the subject location until the appropriate agency gets around to replacing the downed sign.
Accordingly, a need will be seen for a flexible support which is capable of flexing resiliently to absorb the impact of a car or other traffic. The support preferably provides for flexure back to its original position once the impact source is removed (e. g., the vehicle passes completely over the sign and support), in order to be readily visible to other traffic. Moreover, the device must be easily constructed of economical and durable materials in order to provide for widespread use and long life.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 3,799,686 issued on Mar. 26, 1974 to Clarence Williams, titled xe2x80x9cMarker Posts,xe2x80x9d describes a post or column construction comprising a series of identical, vertically stacked hard rubber elements having a pair of flexible cables running vertically through the elements to connect them together.
The device differs considerably from the present invention, in that the Williams device is considerably more complex, having a pair of vertical tensile cable members in addition to a vertical stack of resilient components. The present invention basically comprises a plurality of thin, vertically oriented slats which are laminated together by a relatively few bolts, which are also used to adjust the desired stiffness and resiliency of the assembly.
U.S. Pat. No. 3,875,720 issued on Apr. 8, 1975 to Kennedy M. Russell, titled xe2x80x9cResilient Mounting For Sign Post,xe2x80x9d describes a post formed of a plurality of relatively thin resilient rods, secured by upper and lower U-bolt attachments or the like. The resilient rods allow the post to bend upon impact. The structure is unlike the plurality of thin, flat elements forming the flexible support or column of the present invention.
U.S. Pat. No. 4,061,435 issued on Dec. 6, 1977 to Donald W. Schmanski et al., titled xe2x80x9cRoadway Delineator,xe2x80x9d describes various configurations of posts, each of which includes a plurality of intentionally weakened longitudinal shear lines therein. The post will shear along these lines when struck, thereby allowing the resulting relatively thin vertical elements to flex. Schmanski et al. state that their delineator posts may be reused after impact, but also note that they must be repaired with the addition of other components to provide the required strength after shearing impact. The present flexible support does not require any such repair after impact, as it is formed of a plurality of individual flexible elements which are mechanically secured together.
U.S. Pat. No. 4,084,914 issued on Apr. 18, 1978 to William D. Humphrey et al., titled xe2x80x9cSelf-Erecting Highway Guide Post,xe2x80x9d describes a post having a first component with a flat center section and opposite angled flanges extending therefrom, with an additional curved member resting within the channel defined by the first member. The device provides flexibility, but the provision of only two vertical members with a space therebetween, does not provide the strength of the present support structure. Other embodiments are disclosed, but in each case, either the second member is eliminated, or faces the first member with their concave faces toward one another to define a space therebetween, unlike the present laminated flexible support. Moreover, the Humphrey et al. post elements are formed of a thermoplastic material, rather than the more durable spring steel of the present support members.
U.S. Pat. No. 4,092,081 issued on May 30, 1978 to Donald W. Schmanski, titled xe2x80x9cRoadway/Traffic Delineator,xe2x80x9d describes a post formed of bonded laminations of synthetic fiber material. The laminations include directional fibers, but also include other layers having non-directional or other than longitudinal directional orientation. Schmanski does not disclose the use of plural thin metal slats, or any curvature thereof, for providing the stiffness and bending qualities of the present invention.
U.S. Pat. No. 4,245,922 issued on Jan. 20, 1981 to Robert S. Auriemma, titled xe2x80x9cTraffic Delineator Post,xe2x80x9d describes a post having an arcuate cross section and formed of a single, monolithic unit of plastic or fiberglass. No multiple laminations, mechanically secured together, are disclosed by Auriemma, which multiple laminations are a part of the present invention. As noted further above, plastics (including the plastic resin matrix material used in fiberglass materials) do not have the durability of metals when continually exposed to sunlight and ultraviolet light. The present metal materials overcome this problem.
U.S. Pat. No. 4,435,107 issued on Mar. 6, 1984 to Lawrence J. Sweeney, titled xe2x80x9cTraffic Delineator,xe2x80x9d describes a marker having a rigid base for driving into a hard surface (pavement, etc.). The upper portion may be arcuately formed for stiffness. However, the Sweeney device is formed of plastic for flexibility, with the limitations of such material being noted further above. Also, Sweeney provides only a single panel of material, unlike the multiple metal laminations of the present support.
U.S. Pat. No. 4,486,117 issued on Dec. 4, 1984 to Herbert Blau, titled xe2x80x9cFlexible Traffic Standard,xe2x80x9d describes an anchor or base for a single leaf strap of spring steel. The single leaf of the Blau device is considerably more flexible than the plural laminations of the present column or support, and cannot provide the combination of rigidity for supporting a relatively large sign, and flexibility for precluding damage when struck, as provided by the present invention. Moreover, the single lamination of the Blau device provides no means for adjusting the friction, and thus the resilience, between the adjacent members, as provided by the present invention.
U.S. Pat. No. 4,958,954 issued on Sep. 25, 1990 to Donald W. Schmanski et al., titled xe2x80x9cHorizontal Reflective Highway Marker,xe2x80x9d describes a T-shaped reflective portion, with each arm or member having a curved cross section. The entire device is molded of ABS plastic or the like, rather than being formed of metal, as in the present invention. Moreover, the Schmanski et al. reflector is only a single panel, rather than the present plural laminations.
U.S. Pat. No. 5,028,166 issued on Jul. 2, 1991 to Layne S.
Leishman, titled xe2x80x9cHighway Guidepost,xe2x80x9d describes a post and driver combination, with the post being formed as a single component of extruded thermoplastic material or the like. Leishman does not use metal for the guidepost itself, but only for the tools used to set his guidepost. No multiple leaf metal support or post structure is disclosed by Leishman, as provided by the present invention.
Finally, U.S. Pat. No. 5,267,523 issued on Dec. 7, 1993 to Denis P. Hugron, titled xe2x80x9cResilient Signalling Post,xe2x80x9d describes a post formed of a polycarbonate plastic material. The post is essentially a single, monolithically formed component, having a curved shape with a central longitudinal interior passage. No plural laminated metal plies are disclosed by Hugron, as provided in the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The present invention comprises a flexible support which may be used as a traffic delineator, or for supporting a larger sign or other object as desired. The present support is formed by mechanically securing a plurality of elongate curved metal slats or leaves together to form a laminated structure, with the curvature being about the longitudinal axis of the structure. The assembly is installed preferably with the concave side of the curvature facing the normal direction of traffic. When the device is struck by a vehicle, the multiple laminations of thin metal leaves permit the support to flex to absorb the impact, while the curvature and resilience of the spring metal slats cause the support to resume its normal upright position after the impact force is removed.
The resiliency of the device may be adjusted by means of one or more tension adjustment devices, which may be bolted through the laminated panels or secured about the panels by lateral fasteners. The present support may be used for supporting and displaying a traffic delineator marker, or for the support of a larger sign or plurality of signs, by adjusting the number of laminations composing the support. Additional brackets for the display of additional signs may be secured to the support, either by fastening through the laminations or by securing the bracket(s) about the laminations by lateral fasteners. The present flexible support is also adaptable for use in displaying a street sign or the like, supported at the upper end of the support column.
Accordingly, it is a principal object of the invention to provide an improved flexible support for resiliently supporting a highway sign, marker, or other article thereon.
It is another object of the invention to provide an improved flexible support formed of a plurality of relatively wide, thin elements mechanically secured together.
It is a further object of the invention to provide an improved flexible support which elements are curved about their longitudinal axes, for providing additional rigidity until struck.
Another object of the invention is to provide an improved flexible support including tension adjustment which may be secured either through or surrounding the support column as desired.
Still another object of the invention is to provide an improved flexible support which tension adjustment means may be used for the attachment of one or more signs or additional sign supporting brackets to the support column.
These and other objects of the present invention will become apparent upon review of the following specification and drawings.